# why数理 vs Essay.ink

The clearest difference is update cadence: why数理 at fortnightly against Essay.ink's every 3 months. why数理 also leads on device support (3 vs 1) and iOS requirement (11.0 vs 16.4). On price, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

why数理 ships an update fortnightly, Essay.ink every 3 months. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | why数理 | Essay.ink |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 3 months |
| Size | 71 MB | 105 MB |
| Requires iOS | **11.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [靖一 陈](https://appshunter.io/developer/1529972276) | [Sichuan Dumpling Interactive Technology Co., Ltd.](https://appshunter.io/developer/1166066313) |

## What reviewers say

### why数理

[App page](https://appshunter.io/ios/app/why/id1539375758)

**Features:** macOS Compatibility

**In-app purchases:** none


### Essay.ink

[App page](https://appshunter.io/ios/app/essayink/id6738198003)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is why数理 free?

why数理 is free to download, with no in-app purchases.

### Is Essay.ink free?

Essay.ink is free to download, with no in-app purchases.

### Do why数理 or Essay.ink have ads?

Neither why数理 nor Essay.ink shows ads.

### Which is updated more often, why数理 or Essay.ink?

why数理 ships an update fortnightly, and Essay.ink every 3 months. Most recently, why数理 was updated on November 3, 2026 and Essay.ink on October 30, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*